A tetra-allyl terminated carbamate

ABSTRACT

The invention disclosed is for a new and novel class of liquid polyene compositions formed of a molecule containing at least two unsaturated carbon-to-carbon bonds disposed at terminal positions on a main chain backbone of the molecule. The molecule includes unsaturated carbon-to-carbon bonds connected by a divalent chemically compatible derivative to a stable, organic, polyvalent, and polymeric member free of reactive carbon-tocarbon unsaturation and free of highly water-sensitive members. The new class of liquid polyene compositions which have a molecular weight in the range of 300 to 20,000, and a viscosity in the range from essentially 0 to 20 million centipoises at 70*C., may usefully form a component of a system which upon curing in the presence of a free radical generator and a polythiol, forms odorless, solid, elastomeric products. The cured products may be used as sealants, coatings, adhesives and molded articles.

United States Patent [191 Kehr et al.

June 3, 1975 A TETRA-ALLYL TERMINATED CARBAMATE Inventors: Clifton L.-Kehr, Silver Spring;

Walter R. Wszolek, Sykesville, both of Md.

[73] Assignee: W. R. Grace & Co., New York,

[22] Filed: May 26, 1970 [21] Appl. No.: 40,738

Related US. Application Data [63] Continuation-in-part of Ser. No. 617,801, Feb. 23, 1967, abandoned, which is a continuation-in-part of Ser. No. 567,841, July 26, 1966, abandoned.

[52] US. Cl. 260/471 C; 260/471 C [51] Int. Cl. C07c 125/06 [58] Field of Search 260/468 E, 471 C, 482 B [56] References Cited UNITED STATES PATENTS 3,297,745 l/1967 Fekete et al. 260/471 C Primary ExaminerLorraine A. Weinberger Assistant ExaminerL. A. Thaxton Attorney, Agent, or FirmEugene M. Bond 5 7] ABSTRACT The invention disclosed is for a new and novel class of liquid polyene compositions formed of a molecule containing at least two unsaturated carbon-to-carbon bonds disposed at terminal positions on a main chain backbone of the molecule. The molecule includes unsaturated carbon-to-carbon bonds connected by a divalent chemically-compatible derivative to a stable, organic, polyvalent, and polymeric member free of reactive carbon-to-carbon unsaturation and free of highly water-sensitive members. The new class of liquid polyene compositions which have a molecular weight in the range of 300 to 20,000, and a viscosity in the range from essentially 0 to 20 million centipoises at 70C., may usefully form a component of a system which upon curing in the presence of a free radical generator and a polythiol, forms odorless, solid, elastomeric products. The cured products may be used as sealants, coatings, adhesives and molded articles.

1 Claim, No Drawings A TETRA- ALLYL CARBAMATE The present application for U.S. Patent s a continuation-in-p'art of cope'riding applicatidnSer. No.6 1 7,801,

filed" Feb. '23 l967,"=now abandoned, which ih 'turn is I a continuationin-part' (bf-application Ser." No."5 67,84l filed July 26, 1966, now'abando'r'ie d;- i

This invention relates to a ne'wand novel class of liquid polyene compositions formed of a molecule con taining at least two" unsaturated carbon-to-carbon bonds disposed at terminal positions on a main chain backbone of the molecule. The molecule includes unsaturated carbon-to-carbon bonds connected by a divalent chemically compatible derivative to a stable, organic, polyvalent, and polymeric member free of reactive carbon-to-carbon unsaturation, and free of highly water-sensitive members. The new class of liquid polyene compositions have a molecular weight in the range 300 to 20,000, and a viscosity in the range from essentially 0 to million centipoises at 70C.

It is well known in the art that cure of internally unsaturated polymers such as polybutadiene or polyisoprene may be effected with polythiols. However, such polymers, due mainly to residual internal unsaturation after curing, are unstable either to thermal oxidation or ultra-violet catalyzed oxidation, and are subject to rapid attack by ozone. Eventually degradation and embrittlement results in the internal double bond polymers, substantially reducing their useful service life.

A limitation of commercially available liquid polyurethane prepolymers is the fact that they are terminated by isocyanate (NCO) groups. These NCO groups are extremely unstable in storage, and are highly water-sensitive such that under practical conditions, they react with traces of moisture from the atmosphere to form gaseous carbon dioxide and amino groupings which in turn react with more NCO to form eventually a highly viscous, sometimes completely insoluble urea-extended chain network. In cases where insolubilization occurs, the polymer has to be discarded at great expense. Further, if the NCO-terminated prepolymers come in contact with traces of either acidic or basic impurities, dimerization and/or trimerization of the NCO functions may take place to form viscous, sometimes insoluble products during storage. Even mild alkalis such as those constituents normally present on the surface of glass vessels and containers may cause storage problems.

A further limitation for some applications is found in polyurethane polymers of the prior art which are derived from aromatic diisocyanates or polyisocyanates such as tolylene-2,4-diisocyanate, tolylene-2,6- diisocyanate, 4,4-diisocyanatodiphenylmethane, and the like. These aromatic diisocyanates (or mixtures thereof) enjoy widesprread use in polyurethane elastomers, foams, and coatings, because of their ready commercial availability, high degree of reactivity and relatively low cost. The derived polyurethane products, however, are known to turn yellow, amber, orange or brown in color when exposed to sunlight, ultraviolet light or other forms of actinic radiation. This yellowing tendency imparts a definite limitation on the usageof such polyurethanes in many applications. There'i evidence in the technical literature that shows t yellowing ordi'scoloration problern directly attributa: ble to the aromatic benzeneoidfniicleus in lt matic diisocyanates, and accordingly seriou s, yellowing problems in polyurethanes may be avoided by use of aliphatic polyisocyanates such as hexamethylene diisocyanate. These aliphatic polyisocyanates, however, are difficult to manufacture, are relatively expensive and are relatively slow in reaction rate during polymer formation reactions in comparison to the aromatic polyisocyanates.

It has now been found that numerous defects of the prior art may be effectively overcome by practice of the present invention which provides a new and novel class of liquid polyenes which are curable by polythiols to solid polythioether resins or elastomers. When the polyenes of the present invention are compounded with polythiols, the prepared system may be stored safely for long periods of, time in the absence of a free radical generator. Upon exposure to a free radical generator such as actinic light, the prepared system may be cured rapidly and controllably to av polythioetherpolyurethane product which is essentially nonyellowing upon prolonged exposure to sunlight, and is low in cost and equal or better in reaction rate in polymer formation when compared with compositions derived from aromatic diisocyanates or polyisocyanates.

Generally stated, the new class of polyenes of the present invention include a composition which comprises the formula:

wherein m is an integer of at least 2; wherein X is a member selected from the group consisting of:

In the members (a) to (e),fis an integer from 1 to 9, R is a radical selected from the group consisting of hydrogen, fluorine, chlorine, furyl, thienyl, pyridyl, phenyl and substituted phenyl, benzyl and substituted benzyl, alkyl and substituted alkyl, alkoxy and substituted alkoxy,and cycloalkyl and substituted cycloalkyl. The alkyl and alkoxy have from 1 to 9 carbon atoms, the cycloalkyl has from 3 to 8 carbon atoms, and the substituents on the substituted members are selected from the group consisting of nitro, chloro, fluoro, acetoxy, acetamido, phenyl, benzyl, alkyl and cycloalkyl.

The .members (a) to (e) are connected to [A] through a divalent chemically compatible derivative member of the group consisting of Si(R) 3 Si (R) 43%,

NR, alkyl and substituted alkyl and cycloalkyl and substituted cycloalkyl. R and said substituents are as defined previously, and B is a member of the group consisting of O, -S, and -NR.

The member [A] is stable, organic, polyvalent, and polymeric, free of reactive carbon-to-carbon unsaturation, free of highly water-sensitive members; free of aromatic urethane linkages; and consisting of atoms disposed in main chain series and selected from the group consisting of carbon, oxygen, nitrogen, phosphorus, and silicon, and consisting of pendent substituent atoms of the group consisting of chlorine, fluorine, bromine, hydrogen, oxygen carbon and nitrogen.

The composition has a molecular weight in the range 300 to 20,000, and a viscosity in the range from essentially to 20 million centipoises at 70C as measured by a Brookfield Viscometer.

General representative formulas for the polyenes of the present invention may be prepared as exemplified below:

I Poly (alkylene-ether) Polyol Reacted with Unsaturated Monoisocyanates Forming Polyurethane Polyenes and Related Polymers 4 sisting of CH2=CH(CH2),., hydrogen, phenyl, cycloalkyl, and alkyl. v

The novel class of polyenes of this inventionmay be characterized by extreme ease and versatility of manufacture when the liquid functionality desired is greater than about three. For example, consider an attempted synthesis of a polyhexene starting with an OH terminated polyalkylene ether hexol such as Niax l-lexol LS-490 (Union Carbide Corp.) having a molecular weight of approximately 700, and a viscosity of 18,720 cps at 20C. An attempt to terminate this polymer with ene groups by reacting one mole of hexol with 6 moles of tolylene diisocyanate (mixed 2,4, 26 isomer product) and 6 moles of allyl alcohol proceeded nicely but resulted in a prematurely extended chain and crosslinked solid product rather than an intended liquid polyhexene. Using the reactive carbon to carbon unsaturated aliphatic monoisocyanate route, however, this premature chain extension may be avoided and the desired polyurethane-containing liquid polyhexene may be very easily prepared by a simple, one-step reaction of one mole of hexol with 6 moles of allyl isocyanate. This latter polyhexene has the added advantage of being cured using the teachings of this invention to a non-yellowing polythioether polyurethane product.

Tri-to-Hexafunctional In the above formulas, the sum of x y z in each chain segment is at least 1; P is an integer from 1 to 4; n is at least 1; R is selected from the group consisting of hydrogen, phenyl, benzyl, alkyl, cycloalkyl, and substituted phenyl; and R is a member of the group con- Similarly, the unsaturated aliphatic monoisocyanate technique may be used to prepare liquid polyenes from other analogous highly functional polyols such as cellulose, polyvinyl alcohol, partially hydrolized polyvinyl acetate, and the like, and highly functional polyamines 5 such as tetraethylene pentamine, polyethyleneimine, and the like.

A general method of forming one type of polyene containing urethane groups is to react a polyol ofthe,

general formula R (-OI-I),, wherein R is a polyvalent organic moiety free from reactive carbon-to-carbon unsaturation and n is at least 2; with a polyisocyanate of the general formula Rid-NCO)" wherein R is a polyvalent organic moiety free from reactive carbonto-carbon unsaturation and n is at least 2 and a member of the group consisting of an ene-o1, yne-ol, ene-amine and yne-amine. The reaction is carried out in an inert moisture-free atmosphere (nitrogen blanket) at atmospheric pressure at a temperature in the range from to about 120C for a period of about minutes to about 25 hours. In the case where an ene-o1 or yne-ol is employed, the reaction is preferably a one step reaction wherein all the reactants are charged together. In the case where an ene-amine or yne-amine is used, the reaction is preferably a two step reaction wherein the polyol and the polyisocyanate are reacted together and thereafter preferably at room temperature, the eneamine or yne-amine is added to the NCO terminated polymer formed. The group consisting of ene-o1, yneol, ene-amine and yne-amine are usually added to the reaction in an amount such that there is one carbon-tocarbon unsaturation in the group member per hydroxyl group in the polyol and said polyol and group member are added in combination in a stoichiometric amount necessary to react with the isocyanate groups in the polyisocyanate.

A second general method of forming a polyene containing urethane groups (or urea groups) is to react a polyol (or polyamine) with an aliphatic ene-isocyanate or yne-isocyanate to form the corresponding polyene. The general procedure and stoichiometry of this synthesis route is similar to that described for polyisocyanates in the preceding. In this instance, a polyol reacts with an ene-isocyanate to form the corresponding polyene.

Polyenes containing ester groups may be formed by reacting an acid of the formula R COOII), wherein R is a polyvalent organic moiety free from reactive carbon-to-carbon unsaturation and n is at least 2; with either an ene-o1 or yne-ol. The reaction is carried out in an inert moisture-free atmosphere (nitrogen blanket) at atmospheric pressure at a temperature in the range from O to about 120C. for a period of 5 minutes to 25 hours. Usually the reaction is carried out in the presence of a catalyst (p-toluene sulfonic acid) and in the presence of a solvent, e.g. xylene at refluxing temperature. The water formed is azeotroped off of the reaction.

Another method of making an ester containing polyene is to react a polyol of the formula R OH),, wherein R is a polyvalent organic moiety free from reactive carbon-to-carbon unsaturation and n is at least 2; with either an ene-acid or an yne-acid. The reaction is carried out in the same manner as set out above for the ester-containing polyenes. In practicing this latter technique, however, it may be found that ene-acids (or yne-acids) in which the ene (or yne) group is adjacent to an activating polar moiety such as and the like are generally not desirable within the scope of this invention. These activated ene compounds are very prone to self-polymerization reactions to form vinylpolymers. Excessive amounts of self-polymerization of the ene groups is an undesirable side reaction in the present invention since the desired polythioether reaction products are precluded whenever self-polymerization of the ene groups occurs. Finally, the presence of activated, easily self-polymerizable ene groups in the composition leads to oxygen inhibition during curing, storage stability problems, or the need for excessively high inhibitor concentrations.

In forming the urethane-containing polyenes of the present invention, catalytic amounts of a catalyst may be employed to speed up the reaction. This is especially true in the case where an ene-o1 is used to form the polyene. Such catalysts are well known to those in the art and include organometallic compounds such as stannous octoate, stannous oleate, dibutyl tin dilaurate, cobalt acetylacetonate, ferric acetylacetonate, lead naphthanate and dibutyl tin diace'tate.

In summary, by admixing polyenes or polyynes containing two or more reactive unsaturated carbon-tocarbon bonds located terminal from the main chain with a polythiol containing two or more thiol groups per molecule and thereafter exposing said liquid mixture to free-radical generators, there is provided an essentially odorless solid elastomeric or resinous polymeric product.

Polythiol as used herein refers to simple or complex organic compounds having a multiplicity of pendant or terminally positioned SI-I functional groups per average molecule.

On the average the polythiol must contain 2 or more -.SI-I groups/molecule and have a viscosity range of essentially 0 to 20 million centipoises (cps) at C as measured by a Brookfield Viscometer when in the presence of an inert solvent, aqueous dispersion or plasticizer. Operable polythiols in the instant invention usually have molecular weights in the range about 50 to about 20,000, and preferably from about to about 10,000.

The polythiols operable in the instant invention may be exemplified by the general formula R -(SI-I),, where n is at least 2 and R is a polyvalent organic moiety free from reactive carbon-to-carbon unsaturation. Thus R may contain cyclic groupings and minor amounts of hetero atoms such as N, P or O but primarily contains carbon-carbon, carbon-hydrogen, carbonoxygen, or silicon-oxygen containing chain linkages free of any reactive carbon-to-carbon unsaturation.

One class of polythiols operable with polyenes to obtain essentially odorless polythioether products are esters of thiol-containing acids of the formula I-IS-R- -COOH where R is an organic moiety containing no reactive carbon-tocarbon unsaturation with polyhydroxy compounds of structure R1o-('OH)n where R 0 is a organic moiety containing no reactive carbon-tocarbon unsaturation, and n is 2 or greater. These components will react under suitable conditions to give a polythiol having the general structure:

.7 where R, and R are organic moieties containing no reactive carbon-to-carbon unsaturation, and n is 2 or greater. I

Certain polythiols such as the aliphatic monomeric polythiols (ethane dithiol, hexamethylene dithiol, decamethylene dithiol, tolylene-2,4-dithiol,. and the like, and some polymeric polythiols such as a thiolterminated ethylcyclohexyl dimercaptan polymer, and the like, and similar polythiols which are conveniently and ordinarily synthesized on a commercial basis, although having obnoxious odors, are operable but many of the end products are not widely accepted from a practical, commercial point of view. Examples of the polythiol compounds preferred because of relatively low odor level include but are not limited to esters of thioglycolic acid (HS-,CH COOH), a-mercaptopropionic acid (HSCl-l(CH )COOl-l and B-mercaptopropionic acid (HSCH CH COCH) with polyhydroxy compounds such as glycols, triols, tetraols, pentaols, hexaols, and the like. Specific examples of the preferred polythiols include but are not limited to ethylene glycol bis (thioglycolate), ethylene glycol bis (B-mercaptopropionate), trimethylolpropane tris (thioglycolate), trimethylolpropane tris '(B-mercaptopropionate), pentaerythritol tetrakis (thioglycolate) and pentaerythritol tetrakis (B-mercaptopropionate), all of which are commercially available. A specific example of a preferred polymeric polythiol is polypropylene ether glycol bis (B-mercaptopropionate) which is prepared from polypropylene-ether glycol (e.g. Pluracol P2010, Wyandotte Chemical Corp.) and B-mercaptopropionic acid by esterification.

The preferred polythiol compounds are characterized by a low level of mercaptan-like odor initially, and after reaction, give essentially odorless polythioether end products which are commercially attractive anad practically useful resins or elastomers for both indoor and outdoor applications.

Prior to curing, the curable liquid polymer may be formulated for use as 100% solids, or disposed in organic solvents, or as dispersions or emulsions in aqueous media. a

To obtain the maximum strength, solvent resistance, creep resistance, heat resistance and freedom from tackiness, the reaction components consisting of the polyenes and polythiols are formulated in such a manner as to give solid, crosslinkedd, three dimensional network polythioether polymer systems on curing. In order to achieve such infinite network formation the individual polyenes and polythiols must have a functionality of at least 2 and the sum of the functionalities of the polyene and polythiol components must always be greater than 4. Blends and mixtures of the polyenes and the polythiols containing said functionality are also operable herein.

The curable liquid polymer compositions prior to curing may readily be pumped, poured, siphoned, brushed, sprayed, doctored, or otherwise handled as desired. Following application, curing in place to a solid resin or elastomer may be effected either very rapidly or extremely slowly as desired by manipulation of the compounding ingredients and the method of curmg.

The liquid polythioether-forming components and compositions, prior to curing, may be admixed with or blended with other monomeric and polymeric materials such as thermoplastic resins, elastomers or thermosetting resin monomeric or polymeric compositions. The resulting blend may be subjected to conditions for curing or co-curing of the various components of the blend to give cured products having unusual physical properties.

The curing reaction may be initiated by any free radical-mechanism which dissociates or abstracts a hydrogen atom from an SH group, or accomplishes the equivalent thereof. Thus it is possible merely to expose the polyene and polythiol admixture to ambient conditions (oxygen from the air is the initiator) and obtain a cured solidelastomeric or resinous product. Azo compounds or peroxides (with or without amine accelerators) which decompose at ambient conditions are also operable as free radical generating agents capable of curing the components of the instant invention to solid odorless elastomeric or resinous polymer products. Additionally, ultraviolet light (with or without curing rate accelerators such as chemical photoinitiators, or sensitizers such as benzophenone, acetophenone, acenaphthlene-quinone) or other forms of energetic radiation yield rapid cures.

It is also possible, if desired, to use various forms of high energy irradiation for curing. Peroxides and hydroperoxides, whether or not accelerated, presently used in the curing of unsaturated polyesters are operable as free radical generators to initiate curing. Examples of some operable peroxides and acelerators include but are not limited to, benzoyl peroxide with dimethylaniline as an accelerator, cumene hydroperoxide with cobalt naphthenate as an accelerator and cyclohexanone peroxide with either of the aforementioned accelerators. The peroxides and hydroperoxides may also be generated in situ if so desired.

The curing period may be retarded or accelerated from less than 1 minute to 30 days or more. Conventional curing initiators or accelerators operable include, but are not limited to oxygen; peroxides, hydroperoxides, peracids; persulfates, azo compounds such as azobis-isovaleronitrile; ultraviolet light (with and without coagent sensitizers); high energy radiation such as x-rays, B-rays, electron beams, gamma radiation, and the like; ozone; oxidizing agents such as PbO and cyclohexanone peroxide with dimethyl aniline. Conventional curing inhibitors or retarders include but are not limited to hydroquinone; p-tert-butyl catechol; 2,6-ditert-butyl-p-methylphenol; phenothiazine; N-phenyl-2-naphthylamine; inert gas atmospheres such as helium, argon, nitrogen, and carbon dioxide; vacuum; and the like.

The following examples are given to further illustrate the present invention. In all cases, unless otherwise noted, all parts and percentages are by weight.

FORMATION OF POLYENE PREPOLYMER EXAMPLE 1 To al liter resin kettle equipped with stirrer, thermometer, gas inlet and outlet and heated to a temperature of 50C was charged 610 g. (0.2 mole) of polytetramethylene ether glycol, commercially available from Quaker Oats Co. and having a hydroxyl number of 37.1 along with 0.3 g. dibutyl tin dilaurate. The temperature of the kettle was raised to l 10C and the contents were freed of water under 1 millimeter vacuum for 1 hour. The resin kettle was cooled to 60C and the system was placed under a protective atmosphere of nitrogen throughout the remainder of the reaction. 25.2 g. of

allyl isocyanate, (0.4 mole) was added dropwise to the kettle at such a rate as to maintain the temperature at 60C. When the NCO content dropped to 0.54 mg/g., 1 mm. vacuum again was applied and the system was heated at 70C for 1 hour. The thus formed polymer.

EXAMPLE 2 To a 1 liter resin kettle equipped with stirrer, thermometer, gas inlet and outlet was charged 591 g. (0.30 mole) of a poly(propylene ether) glycol commercially available from Union Carbide under the tradename PPG 2025 and 0.3 g. of dibutyl tin dilaurate. The kettle was heated to 1 C and the contents were freed of water under 1 mm. vacuum for 1 hour. The kettle was cooled to C and the system was placed under a protective atmosphere of nitrogen throughout the remainder of the reaction. 53.1 ml. (49.8 g., 0.6 mole) of allyl isocyanate commercially available from Cheme tron Corp. was added to the system. An exotherm carried the temperature to 45 C in 22 minutes. After 60 minutes, the NCO content (as determined by titration) was 0.04 mg/g. The system was placed under 1 mm. vacuum and heated to 70C to remove traces of unreacted allyl isocyanate. The resultant polymer product had a viscosity of 600 centipoises at C as measured on a Brookfield Viscometer and an average molecular weight of approximately 2,200.

EXAMPLE 3 114 g. of poly(propylene ether) hexol sold under the tradename NIAX Polyol LS-490 by Union Carbide Chemicals Co. having a molecular weight of 684 was charged to a 1 liter four neck flask and heated to 1 10C under vacuum and nitrogen for 1 hour. It was then cooled to approximately C whereat 0.1 cc. of dibutyl tin dilaurate was added followed by slowly adding 83 g. (1 mole) of allyl isocyanate to keep the temperature in the range -80C during the addition. After addition, the reaction was allowed to continue for 1 hour at 70C. The polymeric hexaene product obtained had an average molecular weight of approximately 1200 and a viscosity of 300 centipoises at 70C.

EXAMPLE 4 To a 1 liter 4 neck flask was charged cc. of dimethylformamide, 100 g. of tolylene-2,4-diisocyanate and 0.1 cc. dibutyl tin dilaurate. 58 g. of hexol, i.e. NlAX Polyol LS-490 by Union Carbide and 34 g. of allyl alcohol were mixed together and added dropwise to the flask. Before the addition to the flask was completed, the reaction, which was exothermic, gelled and the addition was discontinued.

A comparison of Examples 3 and 4 shows that Example 3 is an improvement over Example 4 in that it allows one to form polymer without the necessity ofa solvent, and without simultaneous chain extension through urethane formation to give a prematurely gelled product.

EXAMPLE 5 In a 1 liter, neck flask 220 g. of hexol commercially available from Union Carbide Chemicals Co. under the tradename NIAX Polyol LS-490 (0.32 moles) and 0.1 cc of dibutyl tin dilaurate was heated to C Examples 6-14 Following the general procedure of the prior examples, and using the necessary reactants, a series of B X where n 15 l or greater polyenes having the formula: X B A were prepared wherein the derivative members forming the polyenes are defined in the following:

Ex. Component Component Component No. [A]

6. HO-CH CHOH COOl-l OCN-CH,-Cl-l=CH-@ propylene glycol 6 moles COOl-l 3-phenylisophthalic acid allyl isocyanate 5 moles 2 moles 7. HOSiOH OCN CH, NCO CH 6 methylene bis-(-4-)-cyclohcxyl OCNCH =CH isocyanate) diplenylsilanediol 6 moles 5 moles Z-methyl-ally isocyanate moles 8. H N-(-CH CH NH-)-;, ,Cl-l CH Nl-l None OCN-(-CH -)-,,CH=CH poly (ethylene imine) 9-decenyl isocyanate 1 mole 3 moles CH Br 9. HOCH -CH OH OCN-(-CH NCO HO-CH E=CH H Br hexamethylene diisocyanate l Dibromoneopentyl glycol 4 moles DOW SAl 138 3 moles 2-chloro2propen 1 ol 2 moles amples 614-Continued Following the general procedure of the prior examples, and using the necessary reactants, a series of polyenes having the formula: X B A X'where n is l or greater were prepared wherein thederivative members forming the polyenes are defined in the following:

Ex. Component Component Component l l 10. H N-CH cn wn nooctcn cooii H N-CH C=CH l.4-di(aminomethyl) adipic acid CH cyclohexane ll moles 2 l moles OCH 3 2-( P-methoxybenzyl) allyl amine 2 moles ll. HO-CF CF 0H COOH Ho-cii. -F 0CH=CH tetrafluoroethylene glycol ,,O 3 moles I 4-vinyloxybenzyl alcohol 9' 3 moles O trimellitic anhydride (1 mole) l2. HO-(-CH CH O-) H None OCN-(-CH,-)- -,CH=CH,

poly(ethylene ether) glycol- 4-pentenylisocyanate 1 mole moles l3. Phuracol 208 DDI Diisocyanate H OCH CH=CH Phosphorus-based polyol Dimer Acid-based diisocyanate Wyandotte Chem.Co. General Mills Co. HO-CH C H 1 mole 2 moles H OCH CH=CH l l l -trimethylolpropanediallyl ether 2 moles CH Cl-L 14. HO- l l OCNCH-(-CH CH -NCO HOCH CH NC CH CHCH Cl-l CHOH I NCl-l CH N HO- CH; CH Cl-l CH CH-CH CH HOH 2,7-di(isocyanato)- H H heptane CH 4 moles N,N,N' ,N '-tetrakis( 2-hydroxypropyl N-( Z-furyl )-N-vinyl ethylene diamine ethanolamine Wyandotte Co., Quadrol 4 moles 1 mole CURING PROCESS EXAMPLE EXAMPLE 16 0.005 moles of the allyl-terminated liquid Prepolymer from Example 2 was charged to a 2 02. glass jar along with a stoichiometric amount of a polythiol to react with the allyl groups in the Prepolymer, 0.0036 moles of trimethylolpropane tris (B-mercaptopropionate). The liquid reactants were stirred together briefly at room temperature and allowed to stand under ambient conditions. After eight hours a solid, odorless, self-supporting cured elastomeric polythioether polymer resulted.

EXAMPLE 17 40 g. of Prepolymer from Example 2 and 10 g. of a filler sold commercially under the tradename Hi Si] 233 by Columbia Southern Chemical Corp. were charged under nitrogen to a 200 ml. round bottom three necked flask maintained under a nitrogen atmosphere and mixed thoroughly. The flask was heated by a water bath to 60C under full vacuum for 2 hours..

The flask was then allowed to cool under vacuum. 4 g. of pentaerythritol tetrakis (B-mercaptopropionate) was charged to the flask under nitrogen and the reaction was stirred continuously. After 6 /2 days under nitrogen, no cure was noted. The reaction was then exposed to oxygen from the atmosphere and a solid, cured, odorless elastomeric product resulted within 45 minutes.

EXAMPLE 18 30 g. of Prepolymer from Example 3 and 10 g. of Q43" pentaerythritol tetrakis (B-mercaptopropionate EXAMPLE 19' g. of an aliphatic'isocyanate-derived urethane polyene from Example 2 was mixed in an aluminum dish with 2.2 g. of pentaerythritol tetrakis (B-mercaptopropionate) commercially available from Carlisle Chemical C0. under the tradename Q43 and 0.5 g. of acetophenone. The mixture was irradiated for 3 minutes by ultraviolet light from a Sylvania Sun lamp. The sample cured to a tack-free solid which had a color of less than 1 on the Gardner Scale. After exposure to ultraviolet radiation in a Fadeometer for 47.2 hours, the color increased to a value of 4 on the Gardner Scale.

A similar polymer prepared from Polymeg glycol of molecular weight of about 1000 by Quaker Oats Co., tolylene-2,4-diisocyanate and allyl alcohol, cured with pentaerythritol tetrakis (,B-mercaptopropionate) and acetophenone by irradiation with ultraviolet light also had a Gardner color of less than 1. However, after 47.2

hours in the Fadeometer the Gardner color rose to l3.

The molecular weight of the polyenes of the present methods, including solution viscosity, osmotic pressure and gel permeation chromatography. Additionally, the molecular weight may be calculated from the known molecular weight of the reactants.

The viscosity of the polyenes and polythiols may be measured on a Brookfield Viscometer at 30 or 70C in accord with the instructions therefor.

The components to be cured may be prepared as either single-packaged or multi-packaged liquid polymer systems which may be cured to solid polythioether elastomers without liberating gaseous by-products which cause bubbles and voids in the vulcanizate. Thus, there is provided curable liquid polymer systems composed of polyenes and polythiols in which the components individually are storage stable and which are not sensitive to or deteriorated by traces of moisture or oxygen containing gas such as may be encountered during normal storage or handling procedures. Solid resinous or elastomeric products may be prepared from flowable liquids in a system in which the rate of curing may be inhibited or retarded by the use of chemical inhibitors, antioxidants, inert atmospheres and the like. The cured product may be characterized as in the thermally and oxidatively stable state since there is no reactive carbon-to-carbon unsaturation in the main backbone chain.

Solid cured polythioether polymer products have many and varied uses, examples of which include but are not limited to adhesives; caulks; sealants; coatings; impregnants for porous substrates; filleting compounds; molded articles and the like.

As used herein the term polyene and the term polyne refers to single or complex species of alkenes or alkynes having a multiplicity of terminal reactive carbonto-carbon unsaturated functional groups per average molecule. For example, a diene is a polyene that has two reactive carbon-to-carbon double bonds per average molecule, while a diyne is a polyyne that contains in its structure two reactive carbon-to-carbon triple bonds per average molecule. Combinations of reactive double bonds and reactive triple bonds within the same molecule are also possible such as for monovinylacetylene which is a polyeneyne under this definition. For purposes of brevity all these classes of compounds are referred to hereafteras polyenes.

In defining the position of the reactive functional carbon-to-carbon unsaturation, the term terminal is intended to mean that functional unsaturation is at an end of themain chain in the molecule; whereas by near terminal is intended to mean that the functional unsaturation is not more than 10 carbon atoms and typically less than 8 carbon atoms from an end of the main chain in the molecule. The term pendant means that the reactive carbon-to-carbon unsaturation is located terminal or near-terminal in a branch of the main chain as contrasted to a position at or near the ends of the main chain. For purposes of brevity all of these positions are referred to herein generally as terminal unsaturation.

Functionality as used herein refers to the average number of ene or thiol groups per molecule in the polyene or polythiol, respectively. For example a triene is a polyene with an average of three reactive carbon-tocarbon unsaturated groups per molecule and thus has a functionality (f) of three. A dithiol is a polythiol with an average of two thiol groups per molecule and thus has a functionality (f) of two.

It is to be understood that the functionality of the polyene and the polythiol component is commonly expressed in whole numbers although in practice the actual functionality may be fractional. For example, a polyene component having a nominal functionality of 2 (from theoretical considerations alone) may in fact have an effective functionality of somewhat less than 2. In an attempted synthesis of a diene from a glycol in which the reaction proceeds to 100% of the theoretical value for complete reaction, the functionality (assuming 100% pure starting materials) would be 2.0. If however, the reaction were carried to only of theory for complete reaction, about 10% of the molecules present would have only one ene functional group, and there may be a trace of material that would have no ene functional groups at all. Approximately 90% of the molecules, however, would have the desired diene structure and the product as a whole then would have an actual functionality of 1.9. Such a product is useful in the instant invention and is referred to herein as having a functionality of 2.

The term reactive unsaturated carbon-to-carbon groups means groups which will react under proper conditions as set forth herein with thiol groups to yield the thioether linkage as contrasted to the term unreactive carbon-to-carbon unsaturation which means groups found in aromatic nucleii (cyclic structures exemplified by benzene, pyridine, anthracene, and the like) which do not under the same conditions react with thiols to give thioether linkages.

Highly water-sensitive groups are intended to include, for example, isocyanate, acyl halide such as acyl substitutes'for sunlight include means such as a F adometer having a source l of ultraviolet radiation, or a Weatherometer which combines exposure to ultraviolet radiation with exposure to water.

It is understood that the foregoing detailed description is given merelyby way of illustration and that many variations may be made therein without departing from the spirit of this invention.

What is claimed is: l. A terminally unsaturated polyene component having' the formula:

CH3 cu -cu-ca o cn o H c c-cr1 o c NH-@- CH2=CHCH2 0 CH2 on O O 3 II II 

1. A TERMINALLY UNSATURATED POLYENE COMPONENT HAVING THE FORMULA: 